A lot of fans had not taken to Ronnie, and season ticket sales had been very slow Oldham managing director Simon Corney

Moore had replaced previous boss Brian Talbot in March 2005.

After steering them clear of relegation that season, he guided them to within six points of the play-offs this term.

Ex-Leeds and Sheffield Wednesday midfielder Sheridan, 41, made over 150 appearances during a six-year spell at Boundary Park, before retiring in 2004.

He also had an 11-week spell as caretaker boss early in 2004, between Iain Dowie's departure and Talbot's appointment.

Earlier in the day, the Latics had posted a statement on their website denying that Moore had left - but hours later, his reign came to an end.

His assistant John Breckin has also left the club.

Moore had previously spent nearly eight years as manager of Rotherham betwen May 1997 and January 2005.

Manging director Simon Corney explained in a statement that Moore's exit was "for financial reasons".

He said: "Clearly, a lot of fans had not taken to him (Moore), and season ticket sales have been very slow.

"People seem to think we have vast sums of money, but unfortunately that is not the case.

"We have to work within certain constraints, and at the end of the day it was a financial decision.

"It wasn't a pleasant job telling Ronnie, and he was shocked.

"There is no doubt he had some unbelievable injury problems last season. Furthermore, we asked for stablility and he had succeeded on that issue.

"But John Sheridan has always had a good rapport with the fans, and likes to play entertaining football.